EXPERIMENT : UTILIZATION OF FOOD/AGRICULTURAL WASTE FOR PRODUCTION OF BIOETHANOL OBJECTIVE To learn on the basic process of microbial fermentation. To quantify the conversion of agricultural waste to bioethanol. Procedure: The agricultural wastes were got and then blended for 3 min. The juice was extracted by filtering using a double-fold of cotton gauze cloth, and particulate matter was removed by centrifuging at 10,000 g for 10 min at 4°C. The undiluted juice was stored, and the waste material obtained from the extraction of juice at -20°C until use.   Kluyveromyces marxianus on the Yeast-Malt (YM) agar containing 10 g/L glucose, 5 g/L peptone, 3 g/L yeast extract, 3 g/L malt extract, and 20 g/L agar were maintained.   Culture was prepared by inoculating two loopfuls of the fungus in a 250 mL Erlenmeyer flask with 100 mL growth medium containing 30 g/L glucose, 5 g/L yeast extract, 2 g/L NH4Cl, 1 g/L KH2PO4, 0.3 g/LMgSO47H2O. The preculture was grew on a rotary shaker at 150 rpm for 12 h at 40 °C.   3 mL of culture was transferred into 92 mL of formulated media with 5 g/L yeast extract, 2 g/L NH4Cl, 1 g/L KH2PO4, and 0.3 g/L MgSO47H2O and 5 mL of extracted juice (carbon) in a 250 mL of flask after 12h of incubation time. Vary the amount of carbon source from 1 mL to 10 mL for different groups. The medium was adjusted to 100 mL accordingly by taking into account the volumes of inoculum and carbon. The control culture was growing by replace with 10 g/L of glucose. The culture was shake at 40°C and 200 rpm for 72 h.   The concentration of ethanol produced from fermentation was detected by using potassium dichromate method. The dichromate reagent was prepared by dissolving 10 g of potassium dichromate in 100 mL of 5 M sulphuric acid in a volumetric flask. 1 mL was pipetted into each test tube followed by adding 3 mL of the culture sample and mixed well. The test tubes were placed in water bath at 60°C for 10 minutes and then cooled to room temperature. The absorbance reading was set to zero using a blank sample. 3 mL was pipetted from the mix into a cuvette and get reading at 600nm. A standard curve was prepared by using 5%, 10%, 15%, 20%, 25% ethanol. The values were compared and determined the concentration of bioethanol from the fermentation experiment. Question: Please make an general introduction paragraph based on this experiment.

EXPERIMENT : UTILIZATION OF FOOD/AGRICULTURAL WASTE FOR PRODUCTION OF BIOETHANOL

OBJECTIVE

1. To learn on the basic process of microbial fermentation.
2. To quantify the conversion of agricultural waste to bioethanol.

Procedure:

• The agricultural wastes were got and then blended for 3 min. The juice was extracted by filtering using a double-fold of cotton gauze cloth, and particulate matter was removed by centrifuging at 10,000 g for 10 min at 4°C. The undiluted juice was stored, and the waste material obtained from the extraction of juice at -20°C until use.

• Kluyveromyces marxianus on the Yeast-Malt (YM) agar containing 10 g/L glucose, 5 g/L peptone, 3 g/L yeast extract, 3 g/L malt extract, and 20 g/L agar were maintained.

• Culture was prepared by inoculating two loopfuls of the fungus in a 250 mL Erlenmeyer flask with 100 mL growth medium containing 30 g/L glucose, 5 g/L yeast extract, 2 g/L NH₄Cl, 1 g/L KH₂PO₄, 0.3 g/LMgSO₄7H₂O. The preculture was grew on a rotary shaker at 150 rpm for 12 h at 40 °C.

• 3 mL of culture was transferred into 92 mL of formulated media with 5 g/L yeast extract, 2 g/L NH₄Cl, 1 g/L KH₂PO₄, and 0.3 g/L MgSO₄7H₂O and 5 mL of extracted juice (carbon) in a 250 mL of flask after 12h of incubation time. Vary the amount of carbon source from 1 mL to 10 mL for different groups. The medium was adjusted to 100 mL accordingly by taking into account the volumes of inoculum and carbon. The control culture was growing by replace with 10 g/L of glucose. The culture was shake at 40°C and 200 rpm for 72 h.

• The concentration of ethanol produced from fermentation was detected by using potassium dichromate method. The dichromate reagent was prepared by dissolving 10 g of potassium dichromate in 100 mL of 5 M sulphuric acid in a volumetric flask. 1 mL was pipetted into each test tube followed by adding 3 mL of the culture sample and mixed well. The test tubes were placed in water bath at 60°C for 10 minutes and then cooled to room temperature. The absorbance reading was set to zero using a blank sample. 3 mL was pipetted from the mix into a cuvette and get reading at 600nm. A standard curve was prepared by using 5%, 10%, 15%, 20%, 25% ethanol. The values were compared and determined the concentration of bioethanol from the fermentation experiment.

Question: Please make an general introduction paragraph based on this experiment.